The effect of metformin on insulin receptor protein tyrosine kinase activity of HIT-T15 cell exposed to high concentration glucose and free fatty acid

• Published in: Sichuan da xue xue bao. Journal of Sichuan University. Yi xue ban Vol. 38; no. 5; p. 819
• Main Authors: Wang, Yu, Li, Xiu-jun, Zhang, Min, Wu, Yun-hong, Tong, Nan-wei, Zhao, Tie-yun, Li, Jie
• Format: Journal Article
• Language: Chinese
• Published: China 01.09.2007
• Subjects: Animals; Cell Line; Cricetinae; Fatty Acids, Nonesterified - metabolism; Glucose - metabolism; Hypoglycemic Agents - pharmacology; Insulin Resistance; Insulin-Secreting Cells - drug effects; Insulin-Secreting Cells - enzymology; Metformin - pharmacology; Protein-Tyrosine Kinases - metabolism; Receptor, Insulin - metabolism
• ISSN: 1672-173X

To study the effect of metformin on insulin receptor (IRc) protein tyrosine kinase (PTK) activity of HIT-T15 cell exposed to high glucose and free fatty acid (FFA) concentration, and to explore the mechanism of metformin (MF) improving beta cell insulin resistance. HIT-T15 cells were incubated for 48 h in a medium containing 5.5-16.7 mmol/L glucose and 0.5 mmol/L palmitic acid respectively. The cells were re-incubated for another 24 h with or without 2.5 microg/mL MF. The PTK activities of IRc were measured by radioactive enzyme assay. The enzymatic activities of IRc PTK were significantly decreased to HIT-T15 cells having the exposure to high glucose or high FFA concentration, when compared to control [(52.5 +/- 18.6) or (54.6 +/- 14.0) vs. (119.4 +/- 29.1) pmol/(min x microg), P < 0.01 respectively. The enzymatic activities of IRc PTK in HIT-T15 cells reincubated with 2.5 microg/mL MF for an additional 24 h were significantly increased vs MF free group [(113.0 +/- 29.8) vs. (52.5 +/- 18.6) pmol/(min x micro